DESCRIPTION (Adapted from applicant's description): The objective of this proposal is to provide a period of mentored, multi-disciplinary training in clinical and laboratory research in pediatric immunology. CD 1 has recently been implicated in the antigen presentation of certain bacterial lipo-polysaccharides in a non-MHC dependent fashion. The applicant's data suggest that there is a role for CD1 restricted T cells in immune responses to pneumococcal polysaccharides and that a lack of these cells results in the inability to produce pneumococcal specific IgG. The proposed project will characterize these cells, delineate their role in polysaccharide antibody responses and ascertain whether patients in at-risk populations have alterations in this T cell subset. Identification of the precise role of these cells and the nature of the defect in susceptible hosts has the potential to lead to novel therapeutic regimes. This work has potentially broader applications in the immune responses to other polysaccharide antigens of common infectious agents. In addition, the applicant will pursue further training in study design and research methods, including didactic courses at the Rollins School of Public Health and the Graduate Division of Biological and Biomedical Sciences, at Emory.